From a401585f070e44b96052fd4649863eb7c8da5af6 Mon Sep 17 00:00:00 2001
From: PopSlime <popslime@qq.com>
Date: Mon, 7 Nov 2022 12:15:22 +0800
Subject: [PATCH] Optimize context cascade in PDT evaluator.

---
 Assets/Cryville/Crtr/PdtEvaluator.cs | 39 ++++++++++++++++++----------
 1 file changed, 25 insertions(+), 14 deletions(-)

diff --git a/Assets/Cryville/Crtr/PdtEvaluator.cs b/Assets/Cryville/Crtr/PdtEvaluator.cs
index c8de6fa..46a8e54 100644
--- a/Assets/Cryville/Crtr/PdtEvaluator.cs
+++ b/Assets/Cryville/Crtr/PdtEvaluator.cs
@@ -32,17 +32,15 @@ namespace Cryville.Crtr {
 					RevokePotentialConstant();
 				}
 				else {
-					PropSrc.Arbitrary result;
-					for (int i = ContextCascade.Count - 1; i >= 0; i--) {
-						Dictionary<int, PropSrc.Arbitrary> cas = ContextCascade[i];
-						if (cas.TryGetValue(name, out result)) {
-							result.Get(out type, out value);
-							return;
-						}
+					PropSrc.Arbitrary result = ContextCascadeLookup(name);
+					if (result != null) {
+						result.Get(out type, out value);
+					}
+					else {
+						type = PdtInternalType.Undefined;
+						LoadNum(name);
+						value = _numbuf;
 					}
-					type = PdtInternalType.Undefined;
-					LoadNum(name);
-					value = _numbuf;
 				}
 				return;
 			}
@@ -97,18 +95,31 @@ namespace Cryville.Crtr {
 		public Judge ContextJudge { private get; set; }
 		public PropSrc ContextSelfValue { private get; set; }
 
-		readonly List<Dictionary<int, PropSrc.Arbitrary>> ContextCascade = new List<Dictionary<int, PropSrc.Arbitrary>>();
+		readonly Dictionary<int, PropSrc.Arbitrary>[] ContextCascade = new Dictionary<int, PropSrc.Arbitrary>[256];
+		int _cascadeHeight;
 		public void ContextCascadeInsert() {
-			ContextCascade.Add(new Dictionary<int, PropSrc.Arbitrary>());
+			ContextCascade[_cascadeHeight++].Clear();
 		}
 		public void ContextCascadeUpdate(int key, PropSrc.Arbitrary value) {
-			ContextCascade[ContextCascade.Count - 1][key] = value;
+			ContextCascade[_cascadeHeight - 1][key] = value;
+		}
+		public PropSrc.Arbitrary ContextCascadeLookup(int name) {
+			PropSrc.Arbitrary result;
+			for (int i = _cascadeHeight - 1; i >= 0; i--) {
+				Dictionary<int, PropSrc.Arbitrary> cas = ContextCascade[i];
+				if (cas.TryGetValue(name, out result)) {
+					return result;
+				}
+			}
+			return null;
 		}
 		public void ContextCascadeDiscard() {
-			ContextCascade.RemoveAt(ContextCascade.Count - 1);
+			--_cascadeHeight;
 		}
 
 		public PdtEvaluator() {
+			for (int i = 0; i < ContextCascade.Length; i++) ContextCascade[i] = new Dictionary<int, PropSrc.Arbitrary>();
+
 			_ctxops.Add(IdentifierManager.SharedInstance.Request("screen_edge"), new func_screen_edge(() => ContextTransform));
 			_ctxops.Add(IdentifierManager.SharedInstance.Request("int"), new func_int(() => ContextSelfValue));
 			_ctxops.Add(IdentifierManager.SharedInstance.Request("clamp"), new func_clamp(() => ContextSelfValue));